A breast pump flange, also known as a breast shield, is the funnel-shaped component that creates a closed system for milk extraction. This piece fits directly over the breast, centered on the nipple, to establish a vacuum seal. The flange serves as the interface between the body and the machine, enabling the pump’s suction mechanism to draw out milk effectively and comfortably.
Defining the Breast Pump Flange
The breast pump flange is typically made from hard plastic or softer silicone material. It is composed of a wide, conical shield section that rests against the breast tissue and an attached narrow tunnel into which the nipple is drawn during pumping. This design allows the pump to mimic the pressure and suction applied by a nursing infant.
When the pump motor activates, a vacuum is created, gently pulling the nipple into the flange tunnel. This action stimulates the nerves in the areola, triggering the milk ejection reflex, which allows milk to flow from the breast. The flange holds the breast tissue securely while channeling the expressed milk into a collection bottle or bag. Softer silicone versions are sometimes preferred for reduced friction and a more flexible fit.
Why Flange Sizing is Critical
The diameter of the flange tunnel is determined by the size of the user’s nipple, not the overall breast size, making accurate measurement essential for effective pumping. Selecting the correct size directly influences both the comfort of the pumping session and the volume of milk expressed. A properly sized flange ensures that the nipple is stimulated efficiently, which is necessary for complete milk removal.
To determine the correct size, individuals should measure the diameter of their nipple in millimeters at the base, where the nipple meets the areola. This measurement should be taken before a pumping session, as the nipple size may temporarily change after stimulation. Measure only the nipple itself, excluding the areola tissue, using a ruler or specialized measuring tool.
After obtaining the nipple diameter, most guidelines suggest adding 2 to 4 millimeters to account for the natural expansion of the nipple during pumping. This final number corresponds to the recommended flange size, which is the diameter of the flange tunnel. It is not uncommon for each breast to require a different flange size, necessitating a separate measurement for both sides. Using the appropriate diameter ensures that the nipple moves freely within the tunnel without rubbing against the sides, which optimizes milk flow and prevents tissue trauma.
Signs of Improper Flange Fit
Using a flange that is either too small or too large can lead to discomfort and long-term issues. If the flange is too small, the nipple will rub against the sides of the tunnel during each suction cycle, causing painful friction and chafing. Users may notice their nipple blanching—turning white or pale—after pumping, a sign that blood flow was restricted due to excessive compression. This condition can lead to cracked skin, bruising at the nipple base, and decreased milk output because the ducts are not fully emptied.
Conversely, a flange that is too large allows too much of the areola to be pulled into the tunnel along with the nipple. This can cause painful swelling and rubbing of the areola tissue against the flange. Signs of a flange that is too large include a sensation of pinching or feeling like the breast is not fully drained after a session. If the areola tissue is noticeably pulled and swells, or if the user experiences pain, a size adjustment is necessary to prevent tissue damage and sustain milk production.
Care and Replacement of Pump Parts
Maintaining the cleanliness and integrity of the flange and other pump components is necessary for hygiene and performance. Flanges should be thoroughly cleaned after every pumping session using warm, soapy water in a wash basin designated only for pump parts. Following cleaning, the parts should be rinsed and allowed to air-dry completely on a clean surface or rack to prevent the growth of mold or bacteria.
The materials of the flange, whether plastic or silicone, will degrade over time with frequent use, washing, and sterilization. Flanges generally require replacement every six months, or sooner if cracks, warping, or discoloration are observed. Other pump accessories, such as the small, flexible valves or membranes, deteriorate much faster, often needing replacement every one to three months. When these smaller parts lose their elasticity, the pump’s suction strength diminishes, which can lead to reduced milk expression.